The technique referred to as a compressed air energy storage (CAES) has been known as a technique to smooth or level fluctuating and unstable generated power output. The CAES technique is to, when power is excessively generated, compress air by a compressor or the like and store energy in the form of air pressure and to reconvert the energy into electricity by an air turbine generator or the like when necessary.
For example, Patent Document 1 discloses a compressed air energy storage system (compressed air energy storage and power generation device). In the compressed air energy storage system, compressed gas from which heat is recovered by a heat exchanger arranged downstream of a compressor is accumulated in a compressed gas accumulator, and the gas drawn from the accumulator is heated by the recovered heat to be supplied to a power generating device.